Charge transport in mixed semiconducting carbon nanotube networks with tailored mixing ratios
The ability to prepare uniform and dense networks of purely semiconducting single-walled carbon nanotubes (SWNTs) has enabled the design of various (opto-)electronic devices, especially field-effect transistors (FETs) with high carrier mobilities. Further optimization of these SWNT networks is desir...
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| Main Authors: | , , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
June 7, 2019
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| In: |
ACS nano
Year: 2019, Volume: 13, Issue: 6, Pages: 7323-7332 |
| ISSN: | 1936-086X |
| DOI: | 10.1021/acsnano.9b03699 |
| Online Access: | Verlag, Volltext: https://doi.org/10.1021/acsnano.9b03699
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| Author Notes: | Maximilian Brohmann, Felix J. Berger, Maik Matthiesen, Stefan P. Schießl, Severin Schneider, and Jana Zaumseil |
| Summary: | The ability to prepare uniform and dense networks of purely semiconducting single-walled carbon nanotubes (SWNTs) has enabled the design of various (opto-)electronic devices, especially field-effect transistors (FETs) with high carrier mobilities. Further optimization of these SWNT networks is desired to surpass established solution-processable semiconductors. The average diameter and diameter distribution of nanotubes in a dense network were found to influence the overall charge carrier mobility; e.g., networks with a broad range of SWNT diameters show inferior transport properties. Here, we investigate charge transport in FETs with nanotube networks comprising polymer-sorted small diameter (6,5) SWNTs (0.76 nm) and large diameter plasma torch SWNTs (1.17-1.55 nm) in defined mixing ratios. All transistors show balanced ambipolar transport with high on/off current ratios and negligible hysteresis. While the range of bandgaps in these networks creates a highly uneven energy landscape for charge carrier hopping, the extracted hole and electron mobilities vary nonlinearly with the network composition from the lowest mobility (15 cm2 V-1 s-1) for only (6,5) SWNT to the highest mobility (30 cm2 V-1 s-1) for only plasma torch SWNTs. A comparison to numerically simulated network mobilities shows that a superposition of thermally activated hopping across SWNT-SWNT junctions and diameter-dependent intratube transport is required to reproduce the experimental data. These results also emphasize the need for monochiral large diameter nanotubes for maximum carrier mobilities in random networks. |
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| Item Description: | Gesehen am 11.09.2019 |
| Physical Description: | Online Resource |
| ISSN: | 1936-086X |
| DOI: | 10.1021/acsnano.9b03699 |